1. Field of the Invention
The present invention relates to a universal joint, and in particular to an improved universal joint which is capable of providing an improved shaft connection for implementing a margin compensation, vibration decrease and a strength with respect to a temperature and rotational force between a pipe and shaft of a slip joint and between a slip joint and a yoke joint.
2. Description of the Background Art
Generally, a universal joint is installed at a slanted angle by a certain degree for thereby transferring a rotational force.
The universal joint is formed of a yoke joint installed at a side for transferring a rotational force and at a side for receiving the same, and a slip joint which slips in an axial direction between the yoke joint.
FIG. 1 is a view illustrating a conventional universal joint. As shown therein, the yoke joint 1 is arranged in such a manner that two yokes are alternately engaged for thereby installing a pin in a radial direction at one end of the same.
In addition, a cross shaped spider is installed therebetween for thereby transferring a rotational force from one side yoke to another side yoke in a state that the universal joint is slanted at a certain angle.
The slip joint 2 is constituted in such a manner that a rotational force transferred from one side yoke joint 1 to the other side yoke joint 1 and the slip joint 2 slips in an axial direction.
Namely, the slip joint 2 includes a pipe 3 connected with one side yoke joint 1 and a shaft 4 connected with the other side yoke joint 1.
As shown in FIG. 2, a pair of engaged serrations(or splines) 3a and 3b are formed in the inner side of the pipe 3 and the outer side of the shaft 4.
In addition, a slip 3b is formed at an opened front end portion of the pipe 3 in an axial direction.
A dust cap 6 is installed at an opened front end portion of the pipe 3 for preventing a foreign substance from being inserted into the pipe 3.
A clip 5 is installed in an outer side of the slip 3b for preventing the pipe 3 and the shaft 4 from being loosened and limiting an axial movement of the pipe 3 and the shaft 4.
Therefore, the pipe 3 and the shaft 4 are closely fixed by the clip 5, and the radial direction marginal distance between the pipe 3 and the shaft 4 is minimized.
At this time, a weight of 8xcx9c15 kgf is applied in an axial direction of the pipe 3 and the shaft 4 in order to adjust the length of the slip joint 2. The above weight is not formed by a hand of a human.
The slip joint 2 is installed into an interior of the yoke joint 1. As shown in FIG. 3, an anti-vibration rubber 7 is installed between the slip joint 2 and the yoke joint 1.
Namely, an anti-vibration rubber 7 formed of a rubber material having a good elastic force is installed between the inner portion of the yoke joint 1 and the outer portion of the slip joint 2 for thereby decreasing a vibration applied therebetween.
In addition, a hole is formed in the slip joint 2, the yoke joint 1 and the anti-vibration rubber 7, respectively, in a radial direction, so that the slip joint 2, the yoke joint 1 and the anti-vibration rubber communicate each other.
A pin-shaped stopper 8 is inserted into the interior of the hole for thereby stably supporting the slip joint 2, the yoke joint 1 and the anti-vibration rubber 7 in an axial direction and rotational direction.
In the case that a rotational angle occurs over an elastic region based on the material property of the anti-vibration rubber 7, the rotational force is transferred based on the strength of the stopper 8 installed through the slip joint 2 and the yoke joint 1.
However, in the conventional universal joint, since the slip joint, the pipe and the shaft are fixed using the clip, a slipping operation therebetween is not properly implemented.
In addition, since a lot noise and vibration occur due to a close contact of the elements when varying the length of the slip joint.
Since a serration is formed in the pipe and the shaft based on an accurate process, the fabrication process is complicated, and the fabrication cost is increased.
The anti-vibration rubber installed between the slip joint and the yoke joint may be degraded at a high and low temperature, and a crack may occur therein. In addition, the strength of the same is largely varied due to a high temperature.
Since the strength of the anti-vibration rubber is low for transferring the rotational force, a stopper is additionally needed.
Accordingly, it is an object of the present invention to provide a universal joint which overcomes the problems encountered in the conventional art.
It is another object of the present invention to provide a universal joint which is capable of implementing a margin compensation between a pipe of and shaft of a slip joint and between a slip joint and a yoke joint and a vibration decrease and enhancing a strength with respect to a temperature and rotational force by providing an elastic member which generates an elastic force in a radial direction and a transfer member which transfers a larger rotational force.
To achieve the above objects, there is provided a universal joint which includes a slip joint in which a shaft is inserted into an interior of a hollow pipe for thereby implementing a rotation force transferring and slipping operation, a hollow yoke joint installed at both sides of the slip joint and having one side which surrounds the pipe and shaft, and an elastic means inserted between the pipe and shaft and both ends of the slip joint and the yoke joint for generating an elastic force in a radial direction.